Historically, soldiers were protected by heavy metallic armors made from, for example, iron or high alloy steels. As more powerful and sophisticated armor piercing projectiles were developed, armors made from these conventional materials had to be made more resistant to penetration. This was generally achieved by making the armor thicker, which had the disadvantage of making the armor heavier.
More recently, ceramic-based armors have been developed. Ceramics are used in the fabrication of armors because they are lightweight and extremely hard materials. One of the drawbacks with ceramic armors, however, is that they dissipate the energy of the projectile partially by cracking. Therefore, ceramic armors lack repeat hit capability, i.e., they will not resist penetration if hit in the same position multiple times, and they disintegrate if struck by multiple rounds.
Ceramic containing armor systems have demonstrated great promise as reduced weight armors. These armor systems function efficiently by shattering the hard core of a projectile during impact on the ceramic material. The lower velocity bullet and ceramic fragments produce an impact, over a large “footprint”, on a backing plate which supports the ceramic plates. The large footprint enables the backing plate to absorb the incident kinetic energy, through plastic and/or viscoelastic deformation, without being breached.
There is an increasing need for low-cost, light-weight armor systems that exhibit exceptional multiple-hit performance, have reliable attachment, and show excellent resistance to all hostile environments. There is a particular need for Small Arms Protective Inserts (SAPI) plates used by soldiers to enhance their body armor protection.
Lightweight protective armor, suitable for use by personnel, has been generally ineffective against armor piercing projectiles when multiple hits are required.